Search PubMed⌕ Search

Biomedical subjects

R Mattioli

Publications and source records attributed to R Mattioli.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pulmonary venous flow velocity patterns in 143 normal subjects aged 20 to 80 years old. An echo 2D colour Doppler cooperative study.

In order to find out the normal values and to evaluate the effects of age, heart rate, sex, and haemodynamic and standard echocardiographic parameters on pulmonary venous flow velocity obtained by the transthoracic approach. Doppler pulmonary venous flow parameters were measured in 143 healthy subjects aged from 20 to 80 years. Doppler pulmonary venous flow parameters which had the best correlation with age were: the peak velocity of the systolic wave (r = 0.39) and its integral (r = 0.5), the peak velocity of the diastolic wave (r = -0.6) and its integral (r = -0.44); the systolic (r = 0.68) and diastolic fractions (r = -0.68); the systolic/diastolic peak velocity ratio (r = 0.73) and the systolic/diastolic integral ratio (r = 0.7). The atrial reversal wave did not correlate with age; the atrial reversal wave was more difficult and probably less reliable to measure than the systolic and diastolic waves. The correlations of pulmonary venous flow parameters with mitral flow parameters were also examined. This study showed that, in healthy subjects, despite an increase in the early and atrial waves from the annulus to the tips of the mitral leaflets, there is a similar association between pulmonary venous flow and mitral flow measured at the annulus or at the tips of the mitral leaflets. The intra-observer reproducibility of all the pulmonary venous flow parameters considered were found to be excellent. Moderate inter-observer variability was observed for the systolic, diastolic and atrial reversal wave peak velocities and integrals; however, the systolic/diastolic ratio improved the precision of the measurements. Multivariate analysis showed that age is the principal determinant of the Doppler parameters of pulmonary venous flow: heart rate, sex, body surface area, the size of the left atrium in systole and the left ventricular ejection fraction all influence the Doppler parameters of pulmonary venous flow, even if only slightly.

Adult↗
PubMed1997

Corneal geometry reconstruction with the Keratron videokeratographer.

BACKGROUND: Color-coded corneal maps produced by computer-assisted videokeratographers (CAVKs) have become an indispensable tool for clinical understanding of corneal shape. However, Placido-based CAVKs are criticized as theoretically incapable of producing accurate corneal height information. PURPOSE: This paper describes how the Keratron (Optikon 2000, Rome, Italy) integrated design innovations to achieve accuracy and map use previously thought to be unobtainable. METHODS: The Keratron implemented a spherically unbiased surface reconstruction method that yields height, axial power, and instantaneous curvature without derivation of one quantity from another. Processing innovations resulted in sub-micron height accuracy. The Keratron includes axial power, instantaneous curvature, refractive maps, a height map (spherical offset), pupil edge detection, a "move axis" feature, process editing, indices, a contact lens program, and photorefractive keratectomy (PRK) simulation. CONCLUSIONS: The algorithms for surface reconstruction and the design solutions implemented in the Keratron resulted in accurate height, axial power, and instantaneous curvature measurement and valid, clinically useful maps, as well as additional user options and features.

Algorithms↗
PubMed1997

Hypercoagulability and chronic atrial fibrillation: the role of markers of thrombin generation.

BACKGROUND: We have studied 64 patients with congestive heart failure, half of them also with chronic nonvalvular atrial fibrillation (AF). Patients were also stratified according to a history of prior stroke. METHODS: The generation of thrombin was investigated by means of the molecular markers prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin III complex (TAT), because AF patients may have a hypercoagulable state. There was only a trend toward higher values of TAT and F1 + 2 for AF patients, while subjects with previous stroke (irrespective of AF) had increased levels of the markers of thrombin generation (TAT stroke+ 18.95 +/- 5.15 vs TAT stroke- 8.34 +/- 2.41; F1 + 2 stroke+ 2.22 +/- 0.29 vs F1 + 2 stroke- 1.32 +/- 0.12). The presence of spontaneous echo contrast (SEC) within left atrium was also investigated in 32 AF patients by transesophageal echocardiography. RESULTS: TAT were significantly higher in subjects (n = 11) with SEC (TAT sec+ 37.5 +/- 13.41 vs TAT sec- 8.7 +/- 2.51, p = 0.008). CONCLUSIONS: Finally, when we grouped into 1) those with both AF and stroke, 2) AF alone, 3) stroke alone and 4) sinus rhythm without stroke, levels of F1 + 2 were higher (and marginally higher TAT) in patients with AF and stroke than in those without stroke, revealing that there is a true clotting activation state in these subjects.

Aged↗
PubMed1996

Reinforcing properties of the substance P C-fragment analog DiMe-C7 in Carassius auratus.

The aim of the present study was to investigate whether two substance P (SP) fragments have reinforcing effects in Carassius auratus when the fish were tested in a place-preference experimental model. Fish were placed in a 3-compartment box in which one compartment gives access to two others that are not connected. The time spent in each compartment was recorded for 10 min in order to determine which one was preferred. Twenty-four hours later the fish were given one of the following ip treatments: 1) group VEH (N = 12), injected with teleost saline, 2) group DiMe-C7 (N = 12), injected with 33 micrograms/kg DiMe-C7, and 3) group SP1-7 (N = 12), injected with 167 micrograms/kg SP1-7. Immediately after treatment the fish were kept for 30 min in the compartment that was the least preferred on the day before and this procedure was repeated for 3 days. On the fifth day the fish were retested for 10 min to determine the time spent in each compartment. Two-way analysis of variance with treatments and testing as factors indicated a main effect (P < 0.0025) as well as a testing effect (P < 0.009). The post-hoc Scheffé multiple comparison test indicated that only the DiMe-C7 group presented an increase in the time spent in the paired compartment after treatment. We suggest that the C-terminal fragment of SP has reinforcing effects in Carassius auratus.

Animals↗
PubMed1995

Reinforcing properties of the neuropeptide substance P in Carassius auratus: evidence of dopaminergic system involvement.

The aim of the present study was to investigate whether neuropeptide substance P (SP) has reinforcing effects in Carassius auratus and whether this effect could be related to dopaminergic neurotransmission. For this purpose fishes were put in a three-compartment box in which one compartment gave access to two others that did not directly link. The time spent in each compartment was registered for 10 min to determine a possible preferred compartment. Twenty-four hours later, the fish were given one of the following intraperitoneal treatments: a) Group VEH, injected with the vehicle of substance P; b) Group SP25, injected with SP, 25 micrograms/kg body wt.; c) Group SP50, injected with SP, 50 micrograms/kg; or d) Group HALO, injected with haloperidol (2 mg/kg) 30 min before an injection of SP (50 micrograms/kg). Immediately after the treatment the fish were kept for 30 min in the compartment preferred least the day before. On the next day the fish were retested for 10 min to verify the time spent in each compartment. The results indicate that SP at the dose of 50 micrograms/kg enhanced the time spent on the paired compartment, and that the pretreatment with haloperidol abolished this enhancement. It is suggested that SP has reinforcing effects in C. auratus that may be mediated by the dopaminergic system.

Animals↗
PubMed1995

Repetitive proteins from the flagellar cytoskeleton of African trypanosomes are diagnostically useful antigens.

Trypanosome infection of mammalian hosts leads, within days, to a strong early response against a small, distinct number of parasite proteins. One of these proteins is the variable surface glycoprotein (VSG). Most of the others are apparently non-variable, intracellular trypanosome proteins. Two of these antigens I2 and I17 are now characterized at the molecular level. Both exhibit a highly repetitive amino acid sequence organization, but they show no sequence similarity either to each other or to any other proteins known to date. Preliminary serological analyses indicate that both allow the early, sensitive and specific detection of infections with different species of trypanosomatids, making them interesting candidates for the development of diagnostic tools for trypanosomiasis detection.

Amino Acid Sequence↗
PubMed1993

Mitomycin C, 5fluorouracil and folinic acid in combination with alpha 2b interferon for advanced colorectal cancer.

AIMS AND BACKGROUND: This study was conducted to investigate the activity and toxicity of 5fluorouracil folinic acid+mitomycin C combined with alpha 2b interferon in advanced colorectal cancer based upon recent studies suggesting a possible biochemical modulation of 5fluorouracil by interferon. PATIENTS AND METHODS: Between June 1990 and April 1991 25 previously untreated patients with advanced colorectal carcinoma were treated with mitomycin C 10 mg/m2 iv bolus on day 1, 5fluorouracil 375 mg/m2 on days 1 to 4 and folinic acid 200 mg/m2 on days 1 to 4 every 4 weeks, combined with alpha 2b interferon 3 million U day continuously. RESPONSE: Of the 25 patients entered into the study, 20 were evaluable for response as 5 patients withdrew due to toxicity (grade 3-4 thrombocytopenia in 4 cases and fatigue in 1). No complete response was recorded, 6 patients had partial remission (30%; 95% confidence interval, 10% to 50%), 4 experienced no change and 10 showed progressive disease. The toxicity of this regimen was significant, particularly myelosuppression. CONCLUSIONS: This combination showed a significant toxicity and low response rate compared with other 5fluorouracil based regimens in advanced colorectal cancer.

Aged↗
PubMed1993

Effects of trypanosome inferction and postpartum liveweight change on resumption of reproduction activity in N'Dama cows.

Data on reproduction, liveweight and trypanosome infection of N'Dama cattle raised under traditional husbandry systems in The Gambia were analyzed to quantify the relative effects of postpartum liveweight change and infection with pathogenic trypanosomes on 2 parameters of reproductive efficiency: the ability to calve within 21 months after the initial parturition and the length of the calving interval. Information for the study was obtained from a database on an epidemiological survey begun in 1985 in The Gambia. Calving records (n=294) from 3 locations were classified on the basis of body weight change and prevalence of trypanosome infection between 1 and 4 months postpartum. Least-squares analyses adjusted for effects of location, season of calving, viability of calf, and parity showed that the proportion of cows that calved within 21 months was 50% for cows which maintained or lost less than 5% of the initial postpartum weight and 31% for cows which lost a higher percentage of weight. Corresponding mean calving intervals were 567 and 666 days, respectively (P<0.05). With regard to trypanosome infection, 49% of uninfected cows and 32% of infected cows (P<0.05) calved again within 21 months, with calving intervals of 581 and 651 days, respectively (P<0.05). The interaction between liveweight change and trypanosome infection status was not significant. Furthermore, the findings suggest that while postpartum body weight loss impairs reproductive performance, trypanosome infection does likewise, and these effects may act independently of each other.

Journal Article↗
PubMed1993

Peripherally administered substance P affects extracellular dopamine concentrations in the neostriatum but not in the nucleus accumbens under anesthesia.

The in situ microdialysis technique was used in urethane-anesthetized rats to monitor changes in the extracellular concentrations of dopamine and its metabolites in neostriatum and nucleus accumbens after the peripheral administration of substance P (50 or 250 micrograms/kg, IP). Four to five hours after urethane anesthesia a decrease of extracellular dopamine and its metabolites was observed which continued in the nucleus accumbens in the following 3 h. The administration of substance P induced a decrease in extracellular concentration of dopamine in neostriatum. This neurochemical change after substance P was not accompanied by parallel alterations in extracellular concentrations of dopamine metabolites. No effects of substance P were observed on dopamine or its metabolites in nucleus accumbens. These data are discussed in relation with the contrasting effects of substance P on awake rats and the possible changes in striatal dopamine activity induced by anesthetics.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Plasma predeposit: the role of productive plasmapheresis.

At the Rizzoli Orthopaedic Institute, as part of our autotransfusion program, we have recently had the possibility to introduce plasma predeposit by means of productive plasmapheresis in patients undergoing major orthopaedic surgery, in which bleeding more than 50-60% of circulating blood mass was expected and so a greater quantity of plasma compared to red blood cells was considered necessary. Red cells and fresh frozen plasma predeposits and perioperative blood recovery was sufficient to cover transfusional needs. In our opinion, plasma predepositing by plasmapheresis is indicated in patients with anaemia, cardiopathy and/or vasculopathy, minute constitution.

Adult↗
PubMed1993

[Myocardial response to ischemia produced by repeated coronary occlusions: an experimental study].

BACKGROUND: The fact that brief repeated episodes of ischemia may induce prolonged functional depression of the left ventricle is still a matter of debate. During an angioplasty several brief (20-90 sec) coronary occlusions are performed, with the potential risk of inducing myocardial jeopardy. METHODS: We performed 4 repeated LAD occlusions in 7 open chest pigs under general anesthesia and controlled ventilation. The following parameters were evaluated: mean systemic arterial pressure (MAP), left ventricular peak systolic pressure (LVPSP), heart rate (HR), and peak negative and positive dP/dt (dP/dt- and +). Each parameter was measured in the basal state and every 4 sec, in the expiratory phase, during the coronary occlusion, the first min and after 10 min of reperfusion. The percent change from control values for each parameter was also calculated and, by means of the ANOVA test, the differences among the 4 consecutive occlusions for each parameter were tested. RESULTS: The results showed that: 1) coronary occlusions significantly depressed dP/dt + and -, MAP and LVPSP, while HR did not change; 2) each variable returned to control values within 1 min of reperfusion; 3) the response to ischemia (percent change) was the same in each of the 4 consecutive occlusions for all parameters at every recording time. CONCLUSIONS: We can conclude that: 1) each experimental coronary occlusion induces a depression of myocardial function that is reversible in 1 min of reperfusion; 2) four repeated 2 minutes coronary occlusions do not induce cumulative effects on myocardial response to ischemia.

Analysis of Variance↗
PubMed1992

Effects of substance P on extracellular dopamine in neostriatum and nucleus accumbens.

Microdialysis was used to monitor changes in dopamine release in the neostriatum and nucleus accumbens after peripheral administration of substance P in freely moving rats. Substance P in a dose of 50 micrograms/kg produced a steady moderate increase in dopamine levels in the neostriatum, which persisted for at least 5 h. In contrast, a dose of 250 micrograms/kg caused an acute increase in dopamine levels in the nucleus accumbens, which lasted about 2 h. These data suggest that the peripheral administration of substance P can influence dopamine release in mesolimbic and mesostriatal terminals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

Preoperative operant circling training facilitates recovery following unilateral substantia nigra lesion in rats.

This study was undertaken to examine (1) whether pre- and/or postoperative training, using water reinforcement, to turn in circles (rotation) affects the behavioral symptoms induced by unilateral 6-hydroxydopamine (6-OHDA)-induced DA denervation of the rat substantia nigra (SN); (2) whether there was any influence of this training on the temporal pattern of recovery; and (3) whether the rotational training influences turning induced by systemic injection of dopaminergic drugs. In the first experiment, rats were trained either ipsi- or contraversive (TI or TO) to the side to be damaged 11 days before and 23 days after lesion, and tested in an open field for rotational behavior following systemic administration of apomorphine and amphetamine. In the second experiment rats were trained only before the lesion was made and tested in the open field for spontaneous circling and thigmotactic behavior. The results of the first experiment indicated maintenance of the training performance after the lesion. At the 14th day after the lesion, the ipsiversive trained group showed a higher contraversive circling frequency after apomorphine injection in relation to the contralateral trained group. In the second experiment, rats trained only before the surgery, showed asymmetrical spontaneous circling in the trained direction before and 14 days after surgery, indicating, in a drug free condition, that training direction can be restored after unilateral SN lesions, even to the contralateral body side. Moreover, thigmotactic behavior indicated a lack of habituation in an open field in unilateral lesion rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamine↗
PubMed1992

Recovery from unilateral 6-hydroxydopamine lesion of substantia nigra promoted by the neurotachykinin substance P 1-11.

Previous work has indicated that the neurotachykinin substance P may have nootropic and neurotrophic effects in vivo and in vitro raising the possibility that this neuropeptide may promote functional recovery from brain damage. This hypothesis was tested using the unilateral 6-hydroxydopamine lesion of the nigrostriatal dopamine system, as there is close anatomical and functional interaction between dopamine and substance P in this system. Rats were unilaterally injected with 6-hydroxydopamine into the substantia nigra, and, starting with the day after the lesion, were treated daily with peripheral injections of substance P (50 micrograms/kg, i.p.). The analysis of open-field behavior showed that, compared with vehicle-treated control lesions, substance P prevented the lesion-induced ipsiversive asymmetry in turning behavior and accelerated recovery from the ipsilateral asymmetry in thigmotactic scanning. The facilitatory effects of substance P were dependent on the degree of the lesion, as they were observed in animals with subtotal neostriatal dopamine depletions but not in those with near-total depletions. These results are discussed, firstly, with regard to the possible mechanisms of substance P on dopaminergic and non-dopaminergic systems, and secondly, with respect to their possible relevance in the study of neurodegenerative diseases.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

[Clinical and prognostic significance of echocardiographic parameters in dilated cardiomyopathy: a prospective study on 225 patients. The Italian Multicenter Study of Cardiomyopathies Group].

To assess the prognostic role of echocardiographic indexes and their relation to clinical conditions, 225 patients with dilated cardiomyopathy were studied prospectively. All cases had a normal coronary angiogram and non specific endomyocardial biopsy findings. 163 men (72.4%) and 62 women (27.6%), mean age 41.5 +/- 12.3 (range 8-61), were studied. Clinical, electrocardiographic and echocardiographic parameters, normalized for body surface area, were tested according to NYHA class and presence of segmental or diffuse wall motion abnormalities. One hundred-four patients were in NYHA class I-IIa, 94 were in class IIb-III and 27 were in class IV. Left ventricular end systolic diameter index, right ventricular end diastolic diameter index, left atrial diameter index, left ventricular fractional shortening and ejection fraction, and radius to wall thickness ratio were significantly more impaired in patients with more severe symptoms. Twenty-eight patients (13%) showed segmental wall motion abnormalities and had smaller left ventricular end systolic and left atrial diameter index and higher left ventricular fractional shortening and ejection fraction. During a mean follow up of 23 +/- 15 months (range 1-67 months), 25 patients (11.1%) died from cardiac causes and 16 (7.1%) underwent heart transplant because of refractory heart failure. Prognostic evaluation was performed separately for cardiovascular mortality alone and for cardiac events (cardiovascular mortality and heart transplantation). At Cox multivariate analysis only right ventricular end diastolic diameter index (p < 0.005) predicted cardiovascular mortality, while left atrial diameter index (p < 0.001), right ventricular end diastolic diameter index (p < 0.01) and left ventricular ejection fraction (p < 0.05) were significant independent predictors of cardiac events.

Adolescent↗
PubMed1991

[Percutaneous nephrostomy in neoplasm patients: when?].

The management of cancer patients with a lesion in its end stage is a clinical problem a satisfactory solution to which has not been found yet, because of the ethical and legal problems involved. The authors analyzed the survival rates of 218 patients with advanced neoplastic disease and obstructive renal failure who had undergone external/internal urinary diversion. One month after the procedure 20% of the patients were dead. The figure rose to 75% at 6 months and reached 98% at one year. Urinary diversion in cancer patients with renal failure is aimed not only at avoiding death and assuring a prolonged survival, but also at providing a good quality of life. Several clinical criteria are therefore analyzed which are used in the selection of patients to submit to nephrostomy. The most important factors seem to be the actual stage of the tumor, its primary location, the possibility of an effective antineoplastic therapy, and the patient's consent. Randomized long-term studies are still necessary to analyze not only survival rates but also quality of life after urinary diversion for obstructive renal failure.

Adult↗